Old writer is unscrupulous opportunist getting University to replace central figure (7)

I haven't cracked this one yet — but the brilliant team at Fifteensquared have:

CHA N CER (=unscrupulous opportunist); “getting University (=U) to replace central figure (=middle letter)” means letter “u” relaces letter “n”; the reference is to the English poet and writer Geoffrey Chaucer (c. 1343-1400).